AudioTools - dB, Sound & Audio

One stupid moment I bought this hoping it was a good set of tools but it never worked correctly and you still have to buy most of the tools even after paying a lot of money for the basic stuff.

De gratis onderdelen werken prima. Upgrades betekenen (diep) in de buidel tasten. Met de ook verkrijgbare hardware kun je klasse-1 apparatuur opbouwen, maar de vraag is wel hoe duurzaam zo’n systeem zal blijken.

A great app with accurate free applications.
Sadly, the "unlockables" are very expensive.

I opened the app, started a tool and the first message I got was that this option was only available as an in-app purchase. I didn't expect that for an app that is initially 8.99 €...

After very many "bug fixes and stability improvements" (refer to: App Store > AudioTools > Details > Version History), this app v5.8 is still highly unreliable, bad User Interface, wrong values, clumsy file system, bugs, crashes.
Chaotic incomplete documentation, website, videos, extremely poor forum.
NOT a professional-grade app at all.
ALSO:
Includes Flurry app analytics Trackware ("Spyware") to secretely track your activity and/or information.

On 10 December 2012 I decided to buy the in-app SPEAKER PHASE test, the internal speaker pop test signal. Works great, reconnected several speakers in a pub that appeared to be out of fase. But...
Yesterday I found out that the pop-signal comming out of the iPad was OUT OF PHASE! The iPad is ok, music is IN phase. Stupid mistake by Studio6Digital? I've sent a bug report but no response until now, stll waiting for an answer / update.
ADVICE: use 1 output channel only, to check left and right speaker phase.

This app provide all that's required for measuring audio. The quality is outstanding and the performance vs cost is also 'best in class'